The present invention relates to apparatus with a working platform provided with adjustable legs. The term "platform" used throughout this specification and claims is intended to include pontoons and other like superstructures supported by legs and capable of being raised or lowered in relation to these legs for a variety of purposes.
Apparatus of the above mentioned kind is described in German patent specification No. 1107603. In this known apparatus the platform has openings therein and the legs, which can be raised or lowered in relation to the platform, extend through these openings. In order to raise or lower each leg and to raise or lower the platform, relative to all the legs, each leg is provided with a hoisting device which is capable of effecting relative movement between the leg and the platform. It is necessary with this apparatus to ensure that the legs are aligned correctly in relation to the hoisting devices. However, in practice, due to the clearance of the openings in the platform, the legs can deviate from vertical positions especially where there is unevenness in the ground surface supporting the legs. Even quite small angular deviations can cause problems and it is possible in adverse conditions for the legs to become jammed in the openings if serious misalignment occurs.
With regard to the foregoing a general object of this invention is to provide an improved apparatus.